Slips and falls accidents have been recognized to be of major importance in occupational health. Epidemiological studies have reported this problem being even more serious among older workers, especially female workers. In light of the aging dynamics of the labor force, the long term goal of this proposed study is directed at reducing slip-precipitated falls among older adults. The specific aims are 1) investigate the differences in gait biomechanics relevant to recovery responses following a slipping perturbation between young/older and male/female adults and 2) examine the effect of slippery surfaces warnings on slip-fall potential and biomechanics of recovery responses. Sixty subjects equally divided by gender and into two age groups will be recruited in this study: "young" between the ages of 20 and 35 years and "older" aged 55 to 70 years old. Each subject will be asked to walk on dry and soapy vinyl tile floors, while varying the extent of the a-priori knowledge of the floor's contaminant condition (unexpected slippery surfaces, warning of possible slippery conditions, the subject is aware of the slippery condition). Various kinetic and kinematics gait variables will be derived from the ground reaction forces and 3D body motion data recorded at 150 Hz. Those kinetic and kinematics variables will be evaluated at specific times during gait and used as dependent variables in ANOVAs investigating gender, age and warning safety conditions. In summary, this proposed study will provide a better understanding of the reasons for epidemiological findings suggesting increasing incidence of slip-initiated falls among older adults. By understanding the biornechanical reasons for such reports, the results of this study will have direct implications in I) the development of more effective fall prevention and training programs aimed at improving chances of recovery from slips among older adults and 2) the possible implementation of safety warning guidelines.